456 



MOLLUSCA 



PHYLÜM VI 



,, siuootli ; lateral teetli not fliited 

 Abiiiidaiit 111 the Periniaii. 



Family 32. Trigoniidae Lamarck. 



Shell with few hinge teeth (|), the mantle lohes lüholly free, hut so applied to each 

 other in life as to form functional siphons ; pallial line simple. Devoiiiaii to Receiit. 



Schizodus King (Fig. 700). Ovate or quadrate, 

 anterior adductor scar witli a sniall radial buttress. 



MyophoriaBi-oiiii{Neoschizodus ^^ Gieb.) (Figs. 701, 702). 



Smooth or radially sculptured, \^^ ^J usually with a strong 



radial ridge extending from the ^^^^!^^^ uinbones back ward and 



down ward to the basal margin ; ^^^r the sciüpture on the areas 

 AB 



Fig. 700. 



Schizod7is obscürus Sow. Zeclistcdn; Nieder- 

 rodenbach, near Hanau. A, Internal niould, 

 Vi. B, Hinge, i/i (after King). 



Myophoria lasvigata 

 (Alberti). Schaumkalk ; 

 Rüdersdorf, near B(!r- 

 lin. Vi- 



M yitpliAyrUt decustiata Münst. 

 Upper Trias ; St. Cassian, Tyrol. 



A, Bxterior of riglit valve, Vi' 



B, Enlarged vlew of hinge. 



Trigonia navis Lam. Lower Brown Jura ; 

 Gundershofen, Alsace. Vi- 



Trigonia dandala Park. Middle Crcitaceous 

 (Hervien) ; Meule de Bracquegnies, Belgium. i/i. 



Fig. 705. 



Trigonia costata Sow, 

 Middle Jura ; Würteißterg. 



Fig. 706. 

 Trigonia cf. aliformis Park. Senoni; 

 Vaels, near Aix-la-Chapelle. i/i- 



Fig. 707. 



Trigonia pectinaia 

 Lamarck. Recent;Aus- 

 tralia. Hinge, l/i. 



